Possible failure points in Email Signature Server mail flow

About

There are several points of failure possible within the mail flow for Email Signature Server processing. Below is a graph and descriptions with mitigation actions to consider for each possible failure point.

• Possible failure points graph
• Failure point descriptions and mitigation actions

Possible failure points graph

Failure point descriptions and mitigation actions

1. The email is set to a pending status in Exchange Online/Microsoft 365. The email cannot reach our server for processing over the designated connector. The pending queue will try to re-send the email many times over, by default, 24 hours. After this retry limit is reached the sender will receive an NDR (Non-Delivery Report) email notifying that the email could not be sent with an SMTP reason code.
   • The Templafy ESS mail flow rule should be disabled in Exchange Online
     • Bypass Email Signature Server – Knowledge Base (templafy.com)
   • A support ticket should be opened, including all details and the NDR or LED/SMTP error code, with Templafy Support for investigation and further guidance at support@templafy.com
   • Alerting can be configured by the customer IT for a threshold of emails reaching the Pending Queue.
     • Queues insight in the Mail flow dashboard - Office 365 | Microsoft Docs
2. Exchange Online is rejecting the return of the processed email. This can be due to various reasons related to the user mailbox, Exchange Online send/receive limits, Exchange Online Edge Protection, Microsoft outage incidents, etc. Or the connection returning back to the Exchange Online server could not be established.
   
   • A support ticket should be opened, including all details and the NDR or LED/SMTP error code, with Templafy Support for investigation and further guidance at support@templafy.com
   • Investigate all impacted user mailboxes for issues and Exchange Online send/receive limits being reached.
     • Exchange Online limits - Service Descriptions | Microsoft Docs
3. The Email Signature Server is unable to retrieve a signature for the sender. The email will return to Exchange Online for delivery to the final recipients without an email signature.
   • The User Profile is not valid.
     • Ensure the user has filled out their User Profile of all required fields
   • The sender does not have a valid targeted Email Signature configured in the tenant Admin center
   • The sender is not being targeted by the mail flow rule in Exchange Online and their emails are not being directed to the Email Signature Server for processing
4. Rendered email signatures are not being synchronized to the Email Signature Server Blob Storage through the SAS URL.
   
   • The last rendered signature for the users synchronized to the Blob Storage will be used.
   • Any changes to email signature templates or User Profiles will not be reflected
   • A support ticket should be opened with Templafy Support for investigation and further guidance at support@templafy.com